Gyroscopic continuously variable transmission

ABSTRACT

The present invention is directed to an infinitely variable transmission system that includes a gyroscope and a rotatable gear assembly to translate torque from an input power shaft to an output power shaft.

FIELD OF THE INVENTION

The present invention relates generally to transmission systems andspecifically to a gyroscopic, infinitely or continuously variablemechanical power transmission system.

BACKGROUND OF THE INVENTION

Transmissions are widely employed on a wide variety of mechanizeddevices, including motor vehicles, construction machinery, excavationmachinery, small electric motors, and the like. Manual and automatictransmissions, also known as speed changers or torque converters,typically employ gears, hydraulics, or friction to control transfer oftorque from a power source to a load.

Conventional transmissions suffer from numerous problems. Transmissionsgenerally have low mechanical and energy efficiencies, particularly whenoperating over the full range of output power requirements generallyrequired in normal applications. Transmissions typically operateefficiently only at or near the output speeds corresponding to theinput-to-output rotational speed ratios designed into the device.Additional mechanical and energy inefficiencies can result from theoperational demands for starts, stops, and accelerations. Transmissionsgenerally have slow response times, are bulky and/or heavy, are complex,and/or lack robustness.

Considerable resources have been expended towards developing a moreenergy efficient and operationally effective transmission system thatovercomes these numerous problems. These efforts have been largelyunsuccessful due to the need to make unacceptable compromises in cost,weight, and operational complexity to overcome mechanical and/or designlimitations.

SUMMARY OF THE INVENTION

Objectives of the present invention include providing a transmissionsystem that is continuously or infinitely variable, adaptable to wideranges of use, is more mechanically and energy efficient, isinexpensive, has a fast response time, is small and/or lightweight, iscapable of delivering maximum power on the one hand while operatingefficiently and effectively through a wide range of power demands on theother, is robust and is operationally simple in design.

In a first embodiment, the transmission system includes:

(a) first and second input power shafts, the first input power shaftengaging the second input power shaft;

(b) a frame disposed to be rotated about a third shaft, the frameincluding a gyroscopic member, the gyroscopic member being rotated aboutan axis of rotation when torque is applied to the first input powershaft, the axis of rotation being transverse to a longitudinal axis ofthe third shaft; and

(c) a gear assembly rotatably disposed about an output power shaft. Thegear assembly is engaged with the output power shaft, the second inputpower shaft, and the third shaft such that rotation of the gyroscopicmember about the axis of rotation resists rotation of the frame by thegear assembly, thereby causing at least a portion of the torque appliedto at least one of the first and second input power shafts to betransferred to the output power shaft.

The transmission system is particularly useful as an continuously orinfinitely variable, mechanical power transmission, speed changer ortorque converter. The system is capable of transmitting automatically awide range of output torques by continuously or infinitely variableinput-to-output speed ratios without the switching of gears or a torqueconverter; automatically delivering the output torques at the mostappropriate input-to-output rotational speed ratio(s) relative to theoutput power needs, thereby ensuring power transmission at maximumefficiency and effectiveness; delivering output power torques over awide range of output power requirements without the need for componentssuch as bands, brakes, clutches, hydraulic torque converters, andspecial starters (which may require periodic adjustment, frequentmaintenance, or replacement); transmitting extremely high horsepowers,achievable by high input-to-output speed ratios, with a transmission ofnominal size and weight for the purpose of starting and moving extremelyheavy vehicular loads such as heavy duty trucks, locomotives, and othertypes of heavy equipment; and achieving these results while maintaininga simple design, a light weight, a small cubature, a low cost ofmanufacture, and a robust construction.

The gyroscopic member can be any structure including one or moresymmetrical disks, which are typically relatively heavy (e.g., 150pounds or more), disposed concentrically about a central shaft (havingthe axis of rotation as its longitudinal axis) that is free to rotateabout the axis of rotation which itself is confined within the frame. Inother embodiments, the frame includes nested subframes that are free torotate about one or more axes (i.e., have one or more degrees offreedom). The gyroscopic member has an axis of rotation that remainsfixed with respect to space and will resist directional movement. Thegyroscopic member can deliver a torque that is proportional to theangular velocity of the frame about an axis perpendicular to thegyroscope's axis of rotation. Under the principle of conservation ofangular momentum, the total angular momentum of any system of particlesrelative to any point fixed in space remains constant, provided noexternal force(s) act on the system.

In certain embodiments, the resistance of the frame (i.e., thegyroscope's axis of rotation) to being rotated about the third shaft isattributable to the phenomenon of precession. This phenomenon isexplained by Newton's law of motion for rotation under which the timerate of change of angular momentum about any given axis is equal to thetorque applied about the given axis. Stated another way, the rate ofrotation of the axis of rotation about a transversely oriented axis isproportional to the applied torque. This phenomenon is explained indetail below with reference to FIG. 1.

The gear assembly can include a number of interlocked gears and a numberof parallel, rotatably mounted shafts to facilitate transmission oftorque applied about the second input power shaft to the output powershaft.

In one specific configuration, the gear assembly includes a first gearat a proximal end of the gear assembly and a plate at a distal end ofthe gear assembly. The first gear and plate are rotatably mounted ondifferent shafts (e.g., the second input power shaft and the outputpower shaft, respectively). The third shaft is attached to a second gearthat engages the first gear. A fourth shaft and a fifth shaft arerotatably mounted on the first gear and plate.

A number of gears in the gear assembly are employed to more efficientlytransmit torque from the input power shafts to the output power shaft.In an illustrative configuration, a third gear is attached to the secondinput power shaft, the third gear engages a fourth gear mounted on oneof the fourth and fifth shafts, a fifth gear attached to the one of thefourth and fifth shafts engages a sixth gear on the other of the one ofthe fourth and fifth shafts, and a seventh gear attached to the other ofthe one of the fourth and fifth shafts engages an eighth gear mounted onthe output power shaft.

The relative sizes of the gears in the gear assembly are important tothe efficiency of the transmission. Preferably, the first gear is largerthan the second gear, the third gear is smaller than the fourth gear,the fourth gear is smaller than a fifth gear, and the sixth gear islarger than the seventh gear.

To maximize resistance to rotation of the gear assembly by thegyroscopic member, the second gear is preferably significantly smallerthan the first gear. Preferably, the gear ratio of the first gear to thesecond gear is at least about 2:1 and more preferably is at least about3:1.

In another embodiment, the transmission system includes:

(a) a frame mounting a gyroscopic member, the gyroscopic member disposedto be rotated about an axis of rotation in response to rotation of aninput power shaft, when torque is applied to the input power shaft; and

(c) a gear assembly rotatably engaged with an output power shaft and theinput power shaft, such that the gear assembly is rotatable about theoutput power shaft in response to a power load on the output powershaft. Rotation of the gyroscopic member about the axis of rotationresists rotation of the gear assembly, thereby causing at least aportion of the torque applied to the input power shaft to be transferredto the output power shaft.

In yet another embodiment, a method of operation of a transmissionsystem is provided. The method includes the steps of:

(a) applying torque to the input power shaft;

(b) rotating a gyroscopic member in response to the applying step, thegyroscopic member having an axis of rotation and being mounted on aframe member;

(c) rotating a gear assembly in response to the applying step, the gearassembly engaging the input power shaft and the output power shaft; and

(d) rotating the frame member and the axis of rotation of the gyroscopicmember about a shaft engaging the gear assembly. Rotation of the axis ofrotation resists rotation of the gear assembly. In this manner, at leasta portion of the torque is applied to the output power shaft.

In one process configuration, the gyroscopic member is rotated by theengagement of a first gear attached to the input power shaft with asecond gear attached to the gyroscopic member. In another processconfiguration, the gear assembly is rotated by the engagement of a thirdgear attached to the input power shaft with a fourth gear attached to athird shaft rotatably mounted on a fifth gear. In yet another processconfiguration, the frame member and axis of rotation are rotated by theengagement of a sixth gear attached to the shaft with the fifth gear.

In yet another process configuration, the gear assembly includes fourthand fifth shafts, which are parallel to one another and are mounted oncommon surfaces of the gear assembly. The fourth and fifth shafts arerotated to transmit torque applied to the input power shaft to theoutput power shaft.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts one embodiment of the concept of gyroscopic precessionthat may be employed as part of the transmission system of the presentinvention.

FIG. 2 is a plan view of a transmission system for a motor vehicleaccording to an embodiment of the present invention.

DETAILED DESCRIPTION

FIG. 2 is a plan views of a transmission system for a motor vehicleaccording to an embodiment of the present invention. FIG. 2 is not drawnto scale. The transmission system includes a source of input torque (notshown) engaged with an input power shaft 200, a gyroscope assembly 204,a drive train assembly 208, and a rotating gear assembly or clutchassembly 212 engaged with the drive train assembly 208 for the vehicle.The gear assembly 212 is engaged with the input power shaft 200 viadrive gears 216, 220, 224, 228, and 230 which are positioned on primaryand secondary drive shafts 232 and 236, respectively. A drive gear 216located on the input power shaft 200 engages drive gear 220 to transfera portion of the input torque 240 to the various drive shafts 232 and236, the gear assembly 212, and ultimately to the output power shaft244.

The gyroscope assembly 204 includes a gyro gear 248 for rotating thegyroscope 206 about the rotational shaft 252 having an axis of rotation256 (which is generally coincident with the longitudinal axis of theshaft 252), a frame 260 to support the gyroscope 206, and a gyro shaft264 and attached gear 268 to resist rotation of the frame 260 by thegear assembly 212. The gyroscope 206 preferably has a weight rangingfrom about 150 to about 250 pounds, with most of that weight beingattributable to the rotor. The gyroscope 206 includes a rotational gear270 that engages the gyro gear 248 to cause rotation of a rotor 274attached to the shaft 252 about the axis of rotation 256. The gear ratioof the gyro gear 248 to the rotational gear 270 is preferably at leastabout 4:1 (i.e., 1 rotation of gyro gear 248 equals about 4 rotations ofrotational gear 270) and more preferably at least about 6:1. The shaft252 of the gyroscope 206 is supported on the frame 260 by bearings orany other suitable attachment mechanism located at either end 280 a,b ofthe shaft 252.

The drive train assembly of 208 includes an output power shaft 244 thatincludes a drive gear 300 and a first bevel gear 304 that engages asecond bevel gear 308 attached to the axle 312.

The gear assembly 212 includes a master gear 400; a first gear shaft 404attached to gears 408 and 412, a second gear shaft 420 attached to gears424 and 428, and a plate 432. The master gear 400 is rotatably mountedon the secondary drive shaft 236 and the plate 432 on the power outputshaft 244 by bearings 250 a,b or other suitable device(s). Theserotational mountings permit the gear assembly 212 to rotate about arotational axis that is generally aligned (coincident) with thelongitudinal axes of the secondary drive shaft 236 and the output powershaft 244. The first and second gear shafts are rotatably mounted on theplate 432 and master gear 400 by bearings 260 a-b or other suitabledevices located at either end of each shaft.

The relative sizes of the various interlocking gears can be important tothe mechanical and energy efficiency of the system. The drive gear 216is smaller than the drive gear 220 to transfer a substantial portion ofthe torque to the various drive shafts. Preferably the gear ratio ofdrive gear 220 to drive gear 216 ranges from about 1:2 to about 1:3. Thepreferred gear ratios of drive gear 224 to drive gear 228 is about 1:1.The preferred gear ratio of gyro gear 248 to rotational gear 270 rangesfrom about 1:1 to about 1:2. The preferred gear ratio of master gear 400to gear 268 is at least about 1:2 and more preferably ranges from about1:5 to about 1:3. Regarding the gear ratios of the gears in the gearassembly, the preferred gear ratio of gear 412 to the drive gear 230 isabout 1:1; of gear 408 to gear 428 is about 1:1; of gear 424 to thedrive gear 300 ranges from about 1:1. The gear ratio of gear 408 to gear412 and of gear 428 to the fourth gear 424 preferably ranges from about1:2 to about 1:3.

The operation of the transmission system will now be described withreference to FIG. 2. Upon application of input torque 240 about theinput power shaft 200 by a motor (not shown), the various gears andshafts rotate in the directions shown. The gyro gear 248 rotates therotor in the counterclockwise direction, with the rotational speed ofthe gyroscope rotor 274 and therefore the moment of inertia of thegyroscope rotor being directly proportional to the speed of rotation ofthe input power shaft 200 (and the magnitude of the input torque 240).Because of the resistance of the output power shaft 244, the gear 412will revolve around gear 230, the various gears in the gear assemblywill in turn cause the first and second gear shafts to rotate, and theentire gear assembly (including master gear 400) to rotate about thesecondary drive shaft 236 and the output power shaft 244. Rotation ofthe master gear 400 is resisted by the gear 268 attached to the gyroshaft 264, with the magnitude of the resisting torque exerted on themaster gear 400 by the gear 268 being directly proportional to themagnitude of the input torque 240 (and the rotor speed and moment ofinertia) as discussed above. The resistance to rotation of the mastergear 400 causes a portion of the input torque 240 to be transferredthrough the gear assembly to the output power shaft 244 and therefore tothe axle 312. As the magnitude of the input torque increases ordecreases, the magnitude of the torque applied to the axle 312 willincrease or decrease proportionally. In this manner, the transmission isinfinitely variable over a wide range of input torques (or horsepowers).Stated another way, if proper gear ratios are used, the source of torque(e.g., a motor) can remain in the power band throughout acceleration andpower will not be compromised (i.e., dissipated) due to the shifting ofgears. If the source of torque is allowed to remain at a peakperformance level, then fuel consumption would be drastically reduced innormal every day driving.

In yet another embodiment, the transmission system utilizes a 1- or 2-°of freedom gyroscope as the gyroscopic member. The 1- or 2-° ofrotational freedom gyroscopes permits the transmission to utilize thephenomenon of precession to cause rotation of the rotating gear assembly212.

One or more frames are positioned concentrically within the opposingmembers of frame 260 to provide subframe(s) having one or more degreesof freedom. In one configuration, the device of FIG. 1 is positionedbetween the opposing members with the attachment points 261 and 263being bearing attachments to the opposing members.

The principles underlying the phenomenon of precession are explainedwith reference to FIG. 1. FIG. 1 depicts a gyroscope 100 mounted in aframe 104 having a single degree of rotational freedom, also known as arate gyroscope. As will be appreciated, the transmission system can usea gyroscope having more than one degree of freedom. When an input torque108 is applied about an input axis 112 and the speed of the rotor 116 isheld constant, the angular momentum of the rotor 116 about the axis ofrotation 124 can be changed only by rotating the projection of the axisof rotation 124 about the input axis 112; that is, the rate of rotationof the axis of rotation 124 about the output axis 132 is proportional tothe applied torque 108. This relationship may be stated mathematicallyby the following equation:

T=Iω _(r)Ω

where

T is the torque.

I is the moment of inertia of the gyroscope rotor 116 about the axis ofrotation 124.

ω_(r) is the rotational speed of the gyroscope rotor 116.

Ω is the angular velocity of the axis of rotation 124 (or frame 104)about the output axis 132.

The foregoing description of the present invention has been presentedfor purposes of illustration and description. Furthermore, thedescription is not intended to limit the invention to the form disclosedherein. Consequently, variations and modifications commensurate with theabove teachings, in the skill or knowledge of the relevant art, arewithin the scope of the present invention. By way of example, theinvention includes transmission systems using more or fewer shaftsand/or gears, different configurations of shafts or gears to those setforth above, or more than one gyroscope assembly to increase theresistance of the gyro gear to rotation or a gyroscope assembly havingmore than one rotor. The embodiments described here and above arefurther intended to explain best modes for practicing the invention andto enable others skilled in the art to utilize the invention in such, orother, embodiments and with various modifications required by theparticular applications or uses of the present invention. It is intendedthat the appended claims be construed to include alternative embodimentsto the extent permitted by the prior art.

What is claimed is:
 1. A transmission system disposed between a powersource and a power load, comprising: (a) first and second input powershafts, the first input power shaft engaging the second input powershaft; (b) a frame disposed to be rotated about a third shaft, the frameincluding a gyroscopic member, the gyroscopic member being rotated aboutan axis of rotation when torque is applied to the first input powershaft, the axis of rotation being transverse to a longitudinal axis ofthe third shaft; and (c) a gear assembly rotatably disposed about anoutput power shaft, the gear assembly being engaged with the outputpower shaft, the second input power shaft, and the third shaft such thatrotation of the gyroscopic member about the axis of rotation resistsrotation of the frame by the gear assembly, thereby causing at least aportion of the torque applied to at least one of the first and secondinput power shafts to be transferred to the output power shaft, whereinthe gear assembly includes at least a first gear and a plate and atleast a fourth shaft and a fifth shaft are rotatably mounted on thefirst gear and the plate.
 2. The transmission system of claim 1, whereinthe gyroscopic member includes one or more discrete rotatable disks. 3.The transmission system of claim 1, wherein the gear assembly includes aplurality of interlocked gears and a plurality of parallel shafts. 4.The transmission system of claim 3, wherein the first gear is at aproximal end of the gear assembly and the plate is at a distal end ofthe gear assembly, the first gear and plate being rotatably mounted ondifferent shafts.
 5. The transmission system of claim 4, wherein thefirst gear is rotatably mounted on the second input power shaft, theplate is rotatably mounted on the output power shaft, and the thirdshaft is attached to a second gear that engages the first gear.
 6. Thetransmission system of claim 5, wherein a third gear is attached to thesecond input power shaft, the third gear engages a fourth gear mountedon one of the fourth and fifth shafts, a fifth gear attached to the oneof the fourth and fifth shafts engages a sixth gear on the other of theone of the fourth and fifth shafts, and a seventh gear attached to theother of the one of the fourth and fifth shafts engages an eighth gearmounted on the output power shaft.
 7. The transmission system of claim5, wherein the second gear is smaller in diameter than the first gear.8. The transmission system of claim 7, wherein the gear ratio betweenthe first gear and the second gear is at least about 1:2.
 9. Thetransmission system of claim 6, wherein the first gear is larger thanthe second gear, the third gear is smaller than the fourth gear, thefourth gear is smaller than a fifth gear, and the sixth gear is largerthan the seventh gear.
 10. A transmission system, comprising: (a) aframe mounting a gyroscopic member, the gyroscopic member disposed to berotated about an axis of rotation in response to rotation of an inputpower shaft, when torque is applied to the input power shaft; and (b) agear assembly rotatably engaged with an output power shaft and the inputpower shaft, such that the gear assembly is rotatable about the outputpower shaft in response to a power load on the output power shaft,wherein rotation of the gyroscopic member about the axis of rotationresists rotation of the gear assembly, thereby causing at least aportion of the torque applied to the input power shaft to be transferredto the output power shaft, wherein the gear assembly includes at least afirst gear and a plate and at least a fourth shaft and a fifth shaft arerotatably mounted on the first gear and the plate.
 11. The transmissionsystem of claim 10, wherein the gyroscopic member includes only onerotatable disk.
 12. The transmission system of claim 10, wherein thegear assembly includes a plurality of interlocked gears and a pluralityof parallel shafts.
 13. The transmission system of claim 12, wherein thefirst gear is at a proximal end of the gear assembly and the plate is ata distal end of the gear assembly, the first gear and plate beingrotatably mounted on different shafts.
 14. The transmission system ofclaim 13, wherein the first gear is rotatably mounted on the input powershaft, the plate is rotatably mounted on the output power shaft, and athird shaft is attached to a second gear that engages the first gear.15. The transmission system of claim 14, wherein a third gear isattached to the input power shaft, the third gear engages a fourth gearmounted on one of the fourth and fifth shafts, a fifth gear attached tothe one of the fourth and fifth shafts engages a sixth gear on the otherof the one of the fourth and fifth shafts, and a seventh gear attachedto the other of the one of the fourth and fifth shafts engages an eighthgear mounted on the output power shaft.
 16. The transmission system ofclaim 15, wherein the gear ratio between the first gear and the secondgear is at least about 1:2.
 17. The transmission system of claim 15,wherein the first gear is larger than the second gear, the third gear issmaller than the fourth gear, the fourth gear is smaller than a fifthgear, and the sixth gear is larger than the seventh gear.
 18. A methodfor transferring torque from an input power shaft to an output powershaft, comprising: (a) applying torque to the input power shaft; (b)rotating a gyroscopic member in response to the applying step, thegyroscopic member having an axis of rotation and being mounted on aframe member; (c) rotating a gear assembly in response to the applyingstep, the gear assembly engaging the input power shaft and the outputpower shaft, wherein the gear assembly includes at least two shaftsrotatably mounted between a pair of common surfaces; and (d) rotatingthe frame member and the axis of rotation of the gyroscopic member abouta power transfer shaft engaging the gear assembly, wherein rotation ofthe axis of rotation resists rotation of the gear assembly, whereby atleast a portion of the torque is applied to the output power shaft;wherein in the rotating step (b) the gyroscopic member is rotated by theengagement of a first gear fixedly attached to the input power shaftwith a second gear attached to the gyroscopic member and in the rotatingstep (c) the gear assembly is rotated by the engagement of a third gearoperatively engaged with the input power shaft with a fourth gearattached to one of the at least two shafts, wherein one of the commonsurfaces is part of a fifth gear, and in rotating step (c) the framemember and axis of rotation are rotated by the engagement of a sixthgear attached to the power transfer shaft with the fifth gear.
 19. Themethod of claim 18, wherein rotating step (d) includes: (e) rotating theat least two shafts, which are parallel to one another, to translaterotation of the input power shaft to rotation of the output power shaft.